PH35436: COBOL 6.3 CPU TIME CONSUMED AT DIFFEREND OPT() AND ARCH() COMPILE OPTIONS LEVELS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Customers may experience difference CPU times consumed when
  using different combinations of ARCH() and OPT() levels
  
  USERS AFFECTED: Users of Enterprise COBOL V6.x compiling
  
  programs at OPT(1|2) and ARCH(12) that use a USAGE DISPLAY data
  item as a receiver and then MOVE from the same data item to an
  element of a USAGE DISPLAY table, using the sender as an index
  into the receiver.
  
  PROBLEM DESCRIPTION:
  Performance is better at OPT(0) than OPT(1|2).
  
  WORKAROUND/CIRCUMVENTION: Compile at OPT(0).
  
  PROBLEM SUMMARY :
  
  For best performance, the compiler tries to move data directly
  to the receiver, but it must be sure it's safe to do so;
  otherwise, it can write to a temporaty storage and then move to
  the final receiver, generating an additional instruction.
  
  At OPT(1|2), the optimizer viewed the write to the USAGE DISPLAY
  data item and susequent read from it as connected statements,
  causing the compiler's internal state to reflect that it
  wouldn't be safe to move directly from the sender to the
  receiver. As this connection wasn't made at OPT(0), the
  generated code avoided using temporary storage at OPT(0), saving
  an instruction and performing faster.
  
  CONCLUSION :
  The compiler was fixed to update its internal state to indicate
  that it is safe to move from the sender directly to the receiver
  in this situation, avoiding the additional instruction to move
  from temporary storage to the receiver.
  

Local fix

• Compile at OPT(0)
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL V6.3               *
  *                 compiling programs at OPT(1|2) and ARCH(12)  *
  *                 that use a USAGE DISPLAY data item as a      *
  *                 receiver and then MOVE from the same data    *
  *                 item to an element of a USAGE DISPLAY        *
  *                 table, using the sender as an index into the *
  *                 receiver.                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: Performance is better at OPT(0) than    *
  *                      OPT(1|2).                               *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  ****************************************************************
  For best performance, the compiler tries to move data directly
  to the receiver, but it must be sure it's safe to do so;
  otherwise, it can write to temporary storage and then move to
  the final receiver, generating an additional instruction.
  
  At OPT(1|2), the optimizer viewed the write to the USAGE
  DISPLAY data item and subsequent read from it as connected
  statements, causing the compiler's internal state to reflect
  that it wouldn't be safe to move directly from the sender to the
  receiver. As this connection wasn't made at OPT(0), the
  generated code avoided using temporary storage at OPT(0),
  saving an instruction and performing faster.
  

Problem conclusion

• The compiler was fixed to update its internal state to indicate
  that it is safe to move from the sender directly to the
  receiver in this situation, avoiding the additional instruction
  to move from temporary storage to the receiver.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  PH34021

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• IGY8RWTU IGYCASMB IGYCCBE  IGYCCCRT IGYCCICS IGYCCSRV IGYCDGEN
  IGYCDIAG IGYCDMAP IGYCEN$0 IGYCEN$1 IGYCEN$2 IGYCEN$3 IGYCEN$4
  IGYCEN$5 IGYCEN$8 IGYCEN$D IGYCEN$R IGYCFGEN IGYCFREE IGYCINIT
  IGYCJA$0 IGYCJA$1 IGYCJA$2 IGYCJA$3 IGYCJA$4 IGYCJA$5 IGYCJA$8
  IGYCJA$D IGYCJA$R IGYCLIBR IGYCLSTR IGYCLVL0 IGYCLVL1 IGYCLVL2
  IGYCLVL3 IGYCLVL8 IGYCMALL IGYCOB2E IGYCOPI  IGYCOPT  IGYCOSCN
  IGYCPGEN IGYCRCTL IGYCRDPR IGYCRDSC IGYCREAL IGYCRWT  IGYCSCAN
  IGYCSIMD IGYCUE$0 IGYCUE$1 IGYCUE$2 IGYCUE$3 IGYCUE$4 IGYCUE$5
  IGYCUE$8 IGYCUE$D IGYCUE$R IGYCXREF IGYDRV   IGYEQCWI IGYMSGE
  IGYMSGK  IGYMSGT  IGYQCBE  IGYQSPLT IGYZQEN6 IGYZQENU IGYZQJP6
  IGYZQJPN
  

Fix information

• Fixed component name

  ENT COBOL FOR Z

• Fixed component ID

  5655EC600

Applicable component levels

• R630 PSY UI74566

     UP21/03/30 P F103

• R631 PSY UI74567

     UP21/03/30 P F103

• R632 PSY UI74568

     UP21/03/30 P F103

• R63H PSY UI74569

     UP21/03/30 P F103

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.